Disordered dimer state in electron-doped ${\mathrm{Sr}}_3{\mathrm{Ir}}_2{\mathrm{O}}_7$

Journal Article · Tue Sep 06 00:00:00 EDT 2016 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.94.100401· OSTI ID:1325153

Hogan, Tom; Dally, Rebecca; Upton, Mary; Clancy, J. P.; Finkelstein, Kenneth; Kim, Young-June; Graf, M. J.; Wilson, Stephen D.

Spin excitations are explored in the electron-doped spin-orbit Mott insulator (Sr_1-xLa_x)₃Ir₂O₇. As this bilayer square lattice system is doped into the metallic regime, long-range antiferromagnetism vanishes, yet a spectrum of gapped spin excitation remains. Excitation lifetimes are strongly damped with increasing carrier concentration, and the energy-integrated spectral weight becomes nearly momentum independent as static spin order is suppressed. Local magnetic moments, absent in the parent system, grow in metallic samples and approach values consistent with one J=12 impurity per electron doped. Our combined data suggest that the magnetic spectra of metallic (Sr_1-xLa_x)₃Ir₂O₇ are best described by excitations out of a disordered dimer state.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division; Natural Sciences and Engineering Research Council of Canada (NSERC)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1325153
• Journal Information: Physical Review B, Vol. 94, Issue 10; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY